Utility companies use power meters to regulate and monitor power usage. Early power meters were electromechanical in nature converting the flow of electricity through the power meter into mechanical movement. The mechanical movement was used to turn a recording device which recorded the amount of energy being used. As technology improved over the years, the design of the power meter incorporated new innovations such as increased processing capability within the meter, elimination of mechanical parts, better accuracy and the like.
The utility company has the ability to connect or disconnect the subscriber from the electrical grid by opening or closing a service disconnect switch located at the power meter. In older power meters, the disconnect switch was located outside the metering device and was operated manually by a utility service technician. If the subscriber failed to pay the utility company for his power usage, the utility company could discontinue power service by opening the service disconnect switch. Alternatively, if service work was being performed on the meter or subscriber location, the utility company may elect to disconnect the subscriber from the electrical service grid by opening the service disconnect switch.
As the power meter has evolved, the service disconnect switch was incorporated into the power meter design. By integrating the service disconnect switch into the power meter, the utility company was able to take advantage of the some of the new advancements of the power meter itself such as remote operation and communication. Remotely operating the integrated service disconnect switch removes the need for manual intervention for disconnecting power to the subscriber. Once the disconnect switch is opened, the flow of electricity to the subscriber is interrupted.
After the flow of electricity to the subscriber is interrupted, the utility company typically monitors the conditions at the subscriber's power meter. Specifically, the utility company monitors the subscriber's line conditions to check for any abnormalities. If the utility company detects that the customer is still receiving power, the subscriber may have tampered with and possibly installed a bypass around the power meter. Alternatively, the subscriber may be receiving power by tapping into another subscriber's power service. The tapped subscriber may not even know he is losing power. In yet another scenario, the subscriber may be using a gas powered generator or other power source to generate power which may create a hazardous line condition.
If the utility company detects the presence of a load side voltage when the service disconnect switch is open, the utility company may initiate appropriate action. For example, if the utility company determines that the customer has bypassed the power meter, a utility craftsperson may be dispatched to the customer premise to verify the theft of power. If an alternate power source is detected, the utility company may continue to monitor the power meter. Should the service disconnect switch be closed without removing the alternate voltage source, a dangerous line condition may exist. Before closing the service disconnect switch, the utility company may notify the customer that an alternate voltage source has been detected and that before power can be restored, the alternative power source must be removed.
Commonly, power meters were designed to detect the tapping of each source contacts directly to the load contacts. However these previous designs may not be able to detect when the consumer has cross-tapped the power meter. In addition, these previous power meters may not be able to detect when an alternative power source is connected to the load side of the disconnected power meter.